1. Field of the Invention
The invention generally relates to the field of fastening devices for use in surgical procedures, and in particular concerns suture anchors for use in laparoscopic and arthroscopic surgery.
2. Prior Art
Sutures are commonly used to close incisions and to reunite damaged tissue. Typically, the sutures are passed through the tissue and the free ends of the sutures are tied together. In many instances, the suturing site is exposed to an extent sufficient to permit the surgeon to quickly tie the suture by hand. However, in some procedures such as laparoscopic or arthroscopic surgery, the suturing site is inaccessible by hand. As a result, the surgeon may be required to tie the suture ends into a knot at a location remote from the suture site, and then manipulate suitably configured instruments for sliding the knot to the site.
For example, laparoscopic surgical procedures usually employ a small diameter cannula that extends through a small incision made in the body of a patient (often the abdomen). The suture extends from the suturing site through the cannula. The exposed free ends of each suture are tied by the surgeon and the knot is slid through the cannula to the suturing site. The operating instruments have relatively long and narrow portions which are inserted through a cannula to perform the operation in the interior of the body. The instrumentation for such procedure is actuated from outside the body. It can readily be understood that the dexterity required to tie free suture ends under such conditions not only places a burden upon the operating personnel, but also poses a greater risk to the patient.
Various suture clips and suture anchors have been provided in the prior art for solving these and other such problems. For example, U.S. Pat. No. 5,078,731 to Hayhurst discloses a suture clip for engaging one or more sutures having an upper leg and an opposing lower leg that are joined at a flexible hinge. The clip is formed from a resilient material that normally biases the clip toward an open position. The Hayhurst suture clip is slidable along the suture(s) when it is in its open position. When positioned at the suturing site, the Hayhurst clip may be closed and the upper and lower legs latched to one another to fix the position of the clip, thereby securing the suture(s). Several days or weeks after surgery suture clips of this type are often difficult to identify by conventional radiographic techniques. Also, the point of fixation along the suture is normally located immediately adjacent to the tissue being sutured. In some instances, this can lead to undesirable abrading of the tissue as the clip and tissue move relative to one another. Also, this type of clip may have a tendency to "dig" into the adjoining tissue or "angulate" thereby allowing the clip to erode into immediately underlying tissue, causing a weakening of the tissue which could lead to complications during recovery. Also, devices such as Hayhurst's are often quite difficult to manipulate and to close onto a suture intracorporeally during laparoscopic surgical procedures.
In U.S. Pat. No. 4,291,698 to Fuchs, et al., a button-type suture retainer is disclosed for use in closing wounds in the epidermis. Fuchs' suture-retainer includes a disk having a slot which extends to a passageway adapted for guiding a suture through the circumference of the disk. The passageway is sealed by clamping a flexible latching device that is formed integral with the slotted disk and adapted for clamping a suture in the passageway. The latching device includes a disk segment that is movable parallel with the slotted disk, over the slot and passage, to a latched position where its inner marginal part is past the passageway. The suture is gripped and held by friction and compression. The disk and the disk segment are connected, via a flexible hinge, so that the button can be handled as a unit. Fuchs et al.'s slotted disk aids in the prevention of damage to skin, however, its latching mechanism and structural size and arrangement are such that it must be manipulated by one hand, and is not, therefore, suitable for laparoscopic surgical procedures. Also, since this type of button anchor requires an integral flexible hinge, it is often very difficult to form from sufficiently radiopaque material to make post operative location of the device by radiographic imaging trouble free.
Other suture fixation devices are disclosed in U.S. Pat. Nos. 3,753,438 issued Aug. 21, 1973 to Wood et al.; 3,857,396; 3,910,281; 3,976,079 issued Aug. 24, 1976 to Samuels et al.; 4,387,489 issued Jun. 14, 1983 to Dudek; 4,750,492 issued Jun. 14, 1988 to Jacobs; 4,969,892 issued Nov. 13, 1990 to Burton et al.; 5,282,832 issued Feb. 1, 1994 to Toso et al; 5,474,572 issued Dec. 12, 1995 to Hayhurst; 5,409,499 issued Apr. 25, 1995 to Yi; and 5,514,159 issued May 7, 1996 to Matula et al.
While the foregoing devices perform the function of suture retention, there is a need for an improved suture retainer clip which is simple in construction, easy to apply, and readily usable in laparoscopic or arthroscopic surgical procedures. There is a further need for a soft tissue suture anchor that evenly distributes the tensile load (applied to it during suturing) across a relatively large portion of the adjoining tissue so that abrasion and "digging-in" are much less likely to occur. There is also a need for a suture retention clip that allows for easy post-operative location and orientation, via radiological means. In particular, with a radiopaque suture clip, a surgeon can assess the integrity or disruption of a sutured tissue juncture.